title: Is urodilatin the missing link in exercise-dependent renal sodium retention?
abstract: The purpose of the present study was to investigate the behavior of plasma atrial natriuretic peptide [ANP-(99-126)] concentration ([ANP]) and renal urodilatin [Uro; ANP-(95-126)] excretion during and after exercise and their possible effects on renal Na+ retention. Ten male subjects performed a cycle ergometer test for 60 min at 60% of maximum workload. Blood and urine samples were collected before, during, and up to 24 h after exercise. During exercise, plasma [ANP] and renal Uro excretion were oppositely affected: whereas [ANP] increased from 46.5 +/- 5.1 to 124.1 +/- 10.6 pg/ml, urinary Uro excretion decreased from 120.8 +/- 16.0 to 49.5 +/- 9.8 fmol/min and remained at a lower level until 1 h after exercise. Glomerular filtration rate showed lowest values during exercise (from 164.9 +/- 15.3 to 75.8 +/- 10.1 ml/min), and urine flow and the fractional excretion rate of Na+ (FENa+) and Cl- (FECl-) had their nadir during the first hour after exercise. Positive relationships were observed between Uro excretion and FENa+ (P < 0.05) and FECl-, whereas a tendency toward a negative correlation was obtained between [ANP] and FENa+. It seems possible that Uro may be, among other factors, involved in the exercise-related regulation of renal Na+ retention. The specific roles Uro and ANP play during exercise, however, remain to be investigated.
authors.affiliation: Abteilung Sportmedizin/Sportphysiologie, Universität Bayreuth, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: Bub
authors.forename: M
authors.initials: M
authors.lastname: Meyer
authors.forename: T
authors.initials: T
authors.lastname: Weiss
authors.forename: G
authors.initials: G
authors.lastname: Schneider
authors.forename: N
authors.initials: N
authors.lastname: Maassen
authors.forename: W G
authors.initials: WG
authors.lastname: Forssmann
mesh_terms: D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D004573:Electrolytes / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005919:Glomerular Filtration Rate / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D007677:Kidney Function Tests; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010672:Phenytoin / Q000652:urine*; D010953:Plasma Volume / Q000502:physiology; D012964:Sodium / Q000652:urine*
chemical_list: D004573:Electrolytes; D019344:Lactic Acid; D010672:Phenytoin; D009320:Atrial Natriuretic Factor; D012964:Sodium